Lithographic digital printing plates are imaged on dedicated opto-mechanical plate setters. The imaged plates undergo a chemical development stage, usually performed by a plate developing processor device 100 (shown in FIG. 1A). Device 100 receives plates for development through plate inlet 128. Device 100 is covered with plate developer cover 124. The development process uses chemical development material in a liquid form. The material is filled into the developer tank 104, shown in FIGS. 1B and 1C, within the plate processor device.
After a printing plate 112 is imaged, it is be transported through the plate processor device for processing, consuming a portion of the developer liquid 108, residing in developer section tank 104.
A plate developer device 100 may use a straight transport path 116, shown in FIG. 1B, or an immersed transport path 120 in order to transport printing plate 112 inside developer 100. Each of these distinct transport path schemes has advantages and disadvantages.
The straight transport path 116 enables smooth movement of printing plate 112 and avoids plate deformation, while moves inside developer 100. On the other hand, it requires spraying the developer liquid 108 over the top side of printing plate 112 using spray bars during the movement of printing plate 112 inside developer 100. This may cause uneven distribution of developer liquid 108 over printing plate 112. In addition, spraying the developer liquid 108 on top of printing plate 112, will also cause oxidation of developer liquid 108, due to open air exposure. Both, the uneven liquid distribution as well as the liquid oxidation may affect the quality of plate development.
The immersed transport path 120, wherein the entire printing plate 112 is fully immersed in liquid 108 during plate movement in device 100, enables even distribution of plate developer liquid 108 on printing plate 112. In addition, in this configuration, developer liquid 108 has minimal exposure to air, thus oxidation is minimized. On the other hand, the immersed transport path 120 requires dipping printing plate 112 deep inside developer tank 104, creating a complex plate movement path inside developer 100. This may cause printing plate 112 to deform during the plate transport stage inside device 100.
In general the straight transport path 116 is usually preferable over the immersed transport path 120. Devices using the immersed path are used when processing is done with a developer liquid 108, which oxidize rapidly in open air.
There is a need for employing both transport paths (116 and 120) in a single developer device 100. The combination of both transport paths in a single device enables a processor to use a variety of plates as well as developer liquids at one printing site.